<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>03_数据类型</title>
</head>
<body>
<script>
    var a=1;
    var b=3.3;
    console.log(a,typeof a,b,typeof b)
    var c='hello';
    var d="world";
    console.log(c, typeof c, d, typeof d);
    var e=true;
    var f=false;
    console.log(e, typeof e, f, typeof f);
    var g;
    console.log(g, typeof g);

    let obj={};
    obj.name='申轩易';
    obj.age=23;
    console.log(obj, typeof obj);
    console.log(obj.name,obj.age);
    let obj2={
        name: '陈佳俊',
        age: 21
    };
    console.log(obj2, typeof obj2);
    console.log(obj2.name,obj2.age);

    let arr=['大江',25,false,5200];
    console.log(arr,typeof arr);
    console.log(arr[0],arr[1],arr[2],arr[3]);
    console.log(arr[99]);

    console.log(Number(true),typeof Number(true));
    console.log(Number(false),typeof Number(false));
    console.log((3));
    console.log(Number('3'));
    console.log(Number('哈,傻狗'));

    console.log(Boolean(1),typeof Boolean(1));
    console.log(Boolean(0));
    console.log(Boolean(null));
    console.log(Boolean(NaN));
    console.log(Boolean(undefined));
    console.log(Boolean(''));
    console.log(Boolean(' '));
    console.log(Boolean('hello'));
</script>

</body>
</html>